// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This file provides a builders for DictionaryValue and ListValue. These
// aren't specific to extensions and could move up to base/ if there's interest
// from other sub-projects.
//
// The general pattern is to write:
//
// scoped_ptr<BuiltType> result(FooBuilder()
// .Set(args)
// .Set(args)
// .Build());
//
// For methods that take other built types, you can pass the builder directly
// to the setter without calling Build():
//
// DictionaryBuilder().Set("key", ListBuilder()
// .Append("foo").Append("bar") /* No .Build() */);
//
// Because of limitations in C++03, and to avoid extra copies, you can't pass a
// just-constructed Builder into another Builder's method directly. Use the
// Pass() method.
//
// The Build() method invalidates its builder, and returns ownership of the
// built value.
//
// These objects are intended to be used as temporaries rather than stored
// anywhere, so the use of non-const reference parameters is likely to cause
// less confusion than usual.
#ifndef EXTENSIONS_COMMON_VALUE_BUILDER_H_
#define EXTENSIONS_COMMON_VALUE_BUILDER_H_
#include <string>
#include "base/memory/scoped_ptr.h"
#include "base/strings/string16.h"
#include "base/values.h"
namespace extensions {
class ListBuilder;
class DictionaryBuilder {
public:
DictionaryBuilder();
explicit DictionaryBuilder(const base::DictionaryValue& init);
~DictionaryBuilder();
// Workaround to allow you to pass rvalue ExtensionBuilders by reference to
// other functions.
DictionaryBuilder& Pass() { return *this; }
// Can only be called once, after which it's invalid to use the builder.
scoped_ptr<base::DictionaryValue> Build() { return dict_.Pass(); }
DictionaryBuilder& Set(const std::string& path, int in_value);
DictionaryBuilder& Set(const std::string& path, double in_value);
DictionaryBuilder& Set(const std::string& path, const std::string& in_value);
DictionaryBuilder& Set(const std::string& path,
const base::string16& in_value);
DictionaryBuilder& Set(const std::string& path, DictionaryBuilder& in_value);
DictionaryBuilder& Set(const std::string& path, ListBuilder& in_value);
// Named differently because overload resolution is too eager to
// convert implicitly to bool.
DictionaryBuilder& SetBoolean(const std::string& path, bool in_value);
private:
scoped_ptr<base::DictionaryValue> dict_;
};
class ListBuilder {
public:
ListBuilder();
explicit ListBuilder(const base::ListValue& init);
~ListBuilder();
// Workaround to allow you to pass rvalue ExtensionBuilders by reference to
// other functions.
ListBuilder& Pass() { return *this; }
// Can only be called once, after which it's invalid to use the builder.
scoped_ptr<base::ListValue> Build() { return list_.Pass(); }
ListBuilder& Append(int in_value);
ListBuilder& Append(double in_value);
ListBuilder& Append(const std::string& in_value);
ListBuilder& Append(const base::string16& in_value);
ListBuilder& Append(DictionaryBuilder& in_value);
ListBuilder& Append(ListBuilder& in_value);
// Named differently because overload resolution is too eager to
// convert implicitly to bool.
ListBuilder& AppendBoolean(bool in_value);
private:
scoped_ptr<base::ListValue> list_;
};
} // namespace extensions
#endif // EXTENSIONS_COMMON_VALUE_BUILDER_H_